A friend of mine is interested in making his own seltzer... He's
thinking about using champagne yeast and corn sugar with ordinary tap
water... What sort of problems would he run into? Nutrients, maybe?
Ammoniacal nitrogen? What about pitching the yeast at a high enough
concentration to get around growth inhibition (due to lack of nutrients)
while producing the seltzer quickly enough to make it worthwhile?

Any and all thoughts are welcome on this subject. It seems to have
never been discussed on the homebrewer's digest within the last two years
(at least according to my archives 8~).